Equipment racks and the data centers populated with them have generated more heat as their processing power increases. Computer room air conditioning (CRAC) systems are increasingly unable to meet the demand for cooling. Typical CRAC systems have been extensions of building air conditioning units used to cool office spaces. As data center cooling needs have increased, more specialized systems have appeared to meet cooling needs.
Some of today's cooling needs can be met by liquid cooling. For example, passive rear door air-liquid heat exchangers are reliable and can provide cooling energy cost savings. They are effective at dealing with data center ‘hot-spots’ and facilitate deployment of fully loaded racks. They offer space savings and flexibility for sites that have exceeded their cooling capacity.
Data center business needs add another variable to consider when solving cooling needs. Typically, data center cooling solutions require enough thermal capacity to support the expected maximum heat load. However, this maximum load may not be reached for months or years as facility requirements start small and grow with business demand. This leads to unnecessary up-front capital costs and inefficiencies. Cooling systems operated below their capacity can be inefficient, further adding to the cost of operating a facility. The reverse is also possible. Heat load can decrease through implementation of virtual servers and conversion of servers to mainframes. It should, therefore, also be possible to incrementally remove cooling capacity.
Increased utility costs apply increased pressure to find efficient sources for whatever amount of cooling is required. Existing CRAC solutions do not provide comprehensive approaches to solve these needs.
Due to the high amount of energy used in cooling, small efficiency improvements have a large impact on the bottom line of data centers. Fractional percentage changes save thousands and can provide rapid returns on investment.
Reliability demands on data centers suggest that each component also needs to be dependable and should support back-up operation when part of the cooling system fails.
There is a need for an efficient, scalable, system and method for reliably meeting the changing cooling needs of enterprises operating heat-generating equipment.